The invention relates to a thin-film magnetic head for use in magnetic tape recording. Further, the invention relates to a method of producing such a thin-film magnetic tape head.
Ever growing demands for high performance and low cost magnetic recording for application in tape backup systems urge the need for improved product design and related manufacturing processes.
For the special features of linear longitudinal tape head design, conventional head structures heretofore typically consist of four to five separate components to form a slider on which a tape bearing surface is built. These components are glued together with high performance adhesive to form a rigid, non-moving body to service the high-speed, high-pressure and highly abrasive tape contact for its read and write function.
The multitude of components in the prior art designs increases the complexity in the assembly processes. The stability of a head structure built with many building blocks also lowers the stability of the combination structure.
For proper operation, different pieces of the tape bearing surface must be highly coplanar in order to ensure sufficient tape contact. Any minute shift of one component relative to the others can produce a tiny step on the tape bearing surface, which may result in an increase in the effective separation distance between the tape and head. In the latter case, the read/write signal is attenuated.
Conventional head structures have the common problem of too many components and involve a relatively large amount of adhesive bonding to form the structure. The multitude of components adhered together can render the magnetic head structurally unstable. During service life, individual portions of the combination head can shift relative to each other due to aging of the adhesive and other stresses, forming detrimental stepped tape bearing surfaces.
An object of the present invention is to overcome these and other shortcomings of structural instability in the prior art designs.
Another object of the present invention is to provide a structurally sound magnetic recording head with simplified manufacturing processes and material control.
In accordance with the present invention, a magnetic tape recording head is provided which includes a U-bar, which is a U-shaped frame having a back portion extending in a longitudinal direction and two spaced-apart leg portions extending from the back portion of the frame in a lateral direction. The magnetic tape head also includes a ceramic block, called an I-block, which is fixed to the frame such that the I-block partially fills the space between the leg portions of the frame. The magnetic tape head further includes a cluster fixed to the frame such that at least a portion of the cluster partially fills the space between the leg portions of the frame. In addition, the I-block and the cluster are arranged such that the I-block is interposed between the cluster and the back portion of the frame.
One or more ridges are formed in a top surface of the combination of the U-bar, the I-block, and the cluster. This top surface is parallel to a plane defined by the longitudinal direction in which the back portion of the U-bar extends and by the lateral direction in which the leg portions of the U-bar extend. Each of these ridges provides a tape bearing surface of the magnetic tape head. One of these tape bearing surfaces may include a portion of the cluster for interfacing with a tape, and for improved structural stability this tape bearing surface may also include a portion of the I-block.
The combination of the U-bar, the I-block, and the cluster may be fixed to a base member preferably made of ceramic or metal, such as aluminum, to further improve structural stability.
According to another aspect of the present invention, a method of manufacturing a magnetic tape head is provided including a step of providing a U-bar, which is a U-shaped frame having a back portion extending in a longitudinal direction and two spaced-apart leg portions extending from the back portion of the frame in a lateral direction. The method also includes a step of fixing a ceramic block, called an I-block, to the frame such that the I-block partially fills the space between the leg portions of the frame. The method further includes a step of fixing a cluster to the frame such that at least a portion of the cluster partially fills the space between the leg portions of the frame. In addition, the I-block and the cluster are arranged such that the I-block is interposed between the cluster and the back portion of the frame. Finally, the method includes a step of forming at least one ridge in a surface which includes a portion of the top surface of the U-bar as described above.
According to still another aspect of the present invention, a method of manufacturing a magnetic tape head is provided including a step of providing a frame bar having a back portion extending in a longitudinal direction and a plurality of spaced-apart leg portions extending from the back portion of the frame bar in a lateral direction. The method also includes a step of fixing at least one ceramic block, called an I-block, to the frame bar such that the I-block partially fills a space between two respective ones of the plurality of leg portions of the frame bar. The method further includes a step of fixing a cluster to the frame bar such that at least a portion of the cluster partially fills the space between two respective ones of the plurality of leg portions of the frame bar. In addition, the I-block and the cluster are arranged such that the I-block is interposed between the cluster and the back portion of the frame bar. In accordance with this method, one or more magnetic tape heads may be assembled from a single frame bar. This may be accomplished by including a step of cutting the frame bar into at least two pieces, at least one of the two pieces including a portion of the frame bar, the at least one I-block, and the at least one cluster. Also, this method includes a step of forming at least one ridge in a surface which includes a portion of the top surface of the frame bar as described above. The step of forming at least one ridge may be performed before the step of cutting the frame bar to facilitate forming ridges in one or more magnetic tape heads at once.
Finally, the above methods may include a step of fixing the combination of the U-bar, the I-block, and the cluster to a base member preferably made of ceramic or metal, such as aluminum, to further improve structural stability. Also, one or more of the steps of providing an I-block bar, which is an uncut plurality of I-blocks, and providing a cluster bar, which is an uncut plurality of clusters, cutting the I-block bar into at least two pieces, and cutting the cluster bar into at least two pieces. In addition, a step of fixing the I-block bar to the cluster bar may be performed before the steps of cutting the I-block bar and cutting the cluster bar, so that the I-block bar and the cluster bar are cut in a single operation.